动物遗传学课件

Chapter8Geneticstructureinanimalpopulation

动物群体的遗传结构TheHardy-Weinbergequilibriuminanimalpopulations动物群体的平衡Changesinthegeneticstructureofpopulations影响平衡和基因频率变化的因素Geneticdiversity遗传多样性Speciesandspeciation

物种与物种形成Populationandpopulationgenetics

群体与群体遗传学Population:entiregroupoforganismsofonekind;aninterbreedinggroupofplantsandanimals;theextensivegroupfromwhichasamplemightbetaken.群体是由交配和亲子关系相连的个体构成的集团Mendelianpopulation:

Anaturalinterbreedingunitofsexuallyreproducingplantsoranimalssharingacommongenepool.孟德尔群体是指能相互交配以有性方式产生个体的集团

Populationgenetics:Thebranchofgeneticsthatdealswithfrequenciesofallelesandgenotypesinbreedingpopulation.研究群体的遗传结构及其变化规律的遗传学就是群体遗传学Evolutiongenetics进化遗传学TheHardy-Weinbergequilibriuminanimalpopulations动物群体的平衡AllelefrequenciesandTheHardy-Weinbergequilibrium基因频率与Hardy-Weinberg平衡Calculationofallelefrequenciesinrandom-breedingpopulations

随机交配群体基因频率的计算TheHardy-Weinbergequilibriumforoveronelocus一个以上座位的平衡AllelefrequenciesandTheHardy-Weinbergequilibrium

基因频率与Hardy-Weinberg平衡Allelefrequency:Theproportionofoneallelerelativetoallallelesatalocusinapopulation一个群体内某一定等位基因的频率叫做基因频率，其中A1的频率为：

x1=(2N11+N12)/(2N)=X11+X12/2

A2的频率

x2=1-x1=X12/2+X22

AllelefrequenciesandTheHardy-Weinbergequilibrium

基因频率与Hardy-Weinberg平衡X11=x12X12=2x1x2X22=x22

TheHardy-Weinbergprincipleofgeneticequilibiumdescribestherelationshipbetweenallelefrequenciesandgenotypefrequenciesundertheassumptionofrandommating.Thisprincipleappliestolociwithalleles,lociwithmultiplealleles,andX-linkedloci.

Randommating随机交配

这是指在群体中一种性别的任何一个个体与其相反性别的任一个体交配的机会均等Allelefrequenciesinlociwithmultiplealleles复等位基因的基因频率一般情况：Hardy-Weinberg平衡：xi=Xii+(1/2)∑Xiji≠jXii=xi2,Xij=2xixj

Calculationofallelefrequenciesinrandom-breedingpopulations

随机交配群体基因频率的计算Co-dominantorin-completeddominantalleles等显性或不完全显性等位基因

xi=(2nii+∑nij)/(2n)Completeddominantalleles完全显性等位基因

x2=√nk/nSex-linkedloci伴性基因频率的计算Forexample例子CalculateallelefrequenciesofA,B,C求出等位基因A,B,C的频率GenotypeAABBCCABACBCTotalObserved7402612808200Expected720.524.512847200例1

一个群体中个体的血型比例是：血型ABOAB

比例0.320.150.490.04计算各等位基因的频率。

解答

血型A,B,O分别由基因IA,IB,i控制，假定它们的频率为x1,x2,x3，则x3=√0.49=0.7

x1+x2+x3=1,(x2+x3)2

=(1–x1)2(x2+x3)2=B+O,x1=1–√B+O=1–√0.32+0.49=1–0.9=0.1x2=1–0.1–0.7=0.2由于所以例2

1998级畜牧专业全体同学的血型比例是：血型ABOAB

比例14(0.259)10(0.185)26(0.482)4(0.074)

计算各等位基因的频率。

AllelefrequenciesforX-linkedloci

伴性基因频率雌性：x12+2x1x2+x22

A1A1A1A2A2A2雄性：

x1+x2

A1A2TheHardy-Weinbergequilibriumforoveronelocus

一个以上座位的平衡Changesinthegeneticstructureofpopulations

影响平衡和基因频率变化的因素Matingsystems交配方式Selection选择Mutation突变Geneticdrift遗传漂变Immigration迁移Thefounder创始者效应ConditionsforHardy-WeinbergequilibiumHardy-Weinberg平衡的5个条件Uniforminadaptation适应性一致Bigpopulations大群体Randommating随机交配Noimmigration无迁入与迁出Mutationinbalance突变处于平衡状态Matingsystems交配方式Matingsystem:inbreedingandoutbreeding交配方式：近交与杂交EffectsofmatingsystemsontheHardy-Weinbergequilibium

交配方式的作用：改变基因型频率，不改变基因频率各种近交类型Varioustypesofconsanguineousmating近交效应Inbreeding,orconsanguieousmating,occurswherematesaregeneticallyrelatedInbreedingallowsrareallelestobecomehomozygous,anditgreatlyincreasesthelikelihoodthatrarerecessivedisorderswillappearintheoffspringofrelatedparentsSelection

选择Selection:Differentialsurvivalandreproductionamonggenotypes;themostimportantofthefactorsthatchangeallelefrequenciesinlargepopulations选择是基因型的非随机差异繁殖

Melanicformofmothbistonbetulariarestingonanunpollutted,lichen-coveredtreetrunk(a).Atypicalformofthemothrestingonapolluted,soot-coveredtreetrunk(b)ThreebasicmodesofselectionandtheireffectsMutation突变A1A2uvx2=

uu+v平衡：

Mutation:AchangeintheDNAataparticularlocusinanorganism.Thetermisusedlooselytoincludepointmutationsinvolvingasinglegenechangeaswellasachromosomalchange.EffectsofmutationsonpopulationsMutationsareasourceofnewvariationSomemutationsareharmful,somearebeneficial,andsomeareneutralornearlysoExperimentshaveshownthatmost,ifnotallmutationsarepreadaptive,notpostadaptiveAmalelionwithacubhesired

Geneticdrift遗传漂变Geneticdriftarechangesinsmallpopulations等位基因的随机变动叫做遗传漂变Geneticdriftoperatinginasmallpopulation.Theaallelefrequencychangesfrom0.5to0.3asaconsequenceofsamplingerrors.Thereisachancethattheaallelecouldbecomeextinct.Migration迁移Δqi=qi’–qi=m(qc–qi)AmodelofmigrationbetweenalargecontinentalpopulationandsmallislandFounderprinciple创始者效应AbalancebetweenselectionandmutationMutation-selectionbalanceforarecessivealleleGeneticdiversity

遗传多样性

遗传多态现象(geneticpolymorphism)是指同一交配繁殖群体中存在两种或两种以上遗传变异的类型,其中频率最低的类型并不依靠重复突变维持。Geneticpolymorphism遗传多态现象染色体多态现象chromosomalpolymorphismDNA多态现象DNApolymorphism蛋白质多态现象proteinpolymorphismchromosomalpolymorphism

染色体多态现象牛Y染色体的多态性猪银染核仁组织区多态性结构异染色质多态性DNA多态现象产生的原因单个核苷酸的点突变即核苷酸的替换单一DNA序列的插入或缺失整串DNA序列的插入或缺失基因转换DNA多态现象检测的原理-RFLPs1)

2)电泳图谱1)2)DNA多态现象的类型RFLP(restrictedfragmentlengthpolymorphism)RAPD(randomamplifiedpolymorphicDNA)微卫星多态性(microsatellitepolymorphism)SSCP(singlestrandconformationpolymorphism)DSCP(doublestrandconformationpolymorphism)DNA芯片(DNAchips)Proteinpolymorphism

蛋白质多态现象

蛋白质多态现象是在蛋白质水平上存在的遗传变异

蛋白质多态现象是由于构成蛋白质的多肽链上的氨基酸出现变化引起的GeneticvariationatthePgm-1locusoffruitfly分子水平下多态现象的维持机制选择学说(selectiontheory)--认为杂合子优势维持分子水平下的多态现象中性学说(neutraltheory)--认为分子水平下的多态现象与选择无关，是一种随机的固定群体遗传变异的度量

--群体的杂合性(H)Geneticdiversity遗传多样性Speciesandspeciation

物种与物种形成ThespeciesconceptPhenotypicorpheneticspeciesconceptBiologicalspeciesconceptModesofspeciationTheallopatricmodeofspeciationSympatricspeciation:AcontroversialmodeParapatricspeciationQuantumspeciationChapter2Mendel’sLaw:TheBasicPrinciplesofInheritance

孟德尔遗传规律

Monohybridcrosses:Theprincipleofsegregation

Dihybridcrosses:TheprincipleofindependentassortmentExtensionsofMendel’slawsFormulatingandtestinggenetichypothesesMendelianPrinciplesinAnimalsMendel’sstudyofheredityHisparentswerefarmersinMoravia,thenapartoftheHapsbergEmpireinCentralEuropeAttheageof21,MendelleftthefarmandenteredaCatholicmonasteryinthecityofBrünnIn1847hewasordainedapriest,taughtatthelocalhighschool,takingtimeoutbetween1951and1953tostudyattheUniversityofViennaAfterreturningtoBrünn,heresumedhislifeasateachingmonkandbeganhisexperimentwithgardenpeaIn1865,MendelpresentedhisresultsbeforethelocalNaturalHistorySociety孟德尔选择豌豆作为杂交材料的原因

豌豆的形状和色泽极易区分和分析；豌豆为自花授粉植物，易于杂交。

Thegardenpea

Onepeculiarityofpeareproductionisthatthepetalsoftheflowerclosedowntightly,preventingpollengrainsfromenteringorleaving.Thisenforcesasystemofself-fertilization

Eachvarietyofpeasaredistinguishedbyaparticularcharacteristic.Mendel’sfocusonthesesingulardifferencesbetweenpeastrainsallowedhimtostudytheinheritanceofonetraitatatime.

Mendelsucceededbecausehefocusedhisattentiononcontrastingdifferencesbetweenplants孟德尔试验成功的原因

前人的试验有两个问题：没有对杂交子代按性状分类计数和没有运用统计分析孟德尔成功之处在于：运用假说-推理方法，注意实验材料的选择，引入群体分析和数量统计分析Monohybridcrosses:Theprincipleofsegregation分离定律

Homozygous×Homozygous

AllF1offspringareheterozygousandpurplecolor.

Ratioof1:2:1Tallanddwarfvarietiesarecrossed-fertilizedAllprogenyaretall.Tall3:Dwarf1

Mendel’sexplanationforsegregation对分离现象的解释Inheritanttraitsaredeterminedbygenes遗传性状由基因决定Thereareapairofgenescontrollingatraitinacell体细胞中有两个基因控制一个性状Apairofgenesegregatefromeachotherduringtheformationofgametes在性细胞形成中成对的基因彼此分离Eachgametecarriesanallele每个性细胞含一个基因Thecombinationofgametesisrandom性细胞的结合完全随机

PAA×aa

GametesAa

F1Aa

Eggs1/2A1/2a

sperm1/2A1/4AA1/4Aa1/2a1/4AA1/4aa1AA：2Aa：1aa

3：1Interpretation图示解释

GlossaryDominance:AconditioninwhichonememberofallelepairismanifestedtotheexclusionoftheotherRecessive:AtermappliedtoonememberofanalleliclackingtheabilitytomanifestitselfwhentheotherordominantmemberispresentGenesandallele:HomozygousandheterozygousGenotypeandphenotypeparental

性状的概念

Character.Oneofthemanydetailsofstructure,form,substance,orfunctionthatmakeupanindividualorganism

有关概念

杂交（hybridization）是指具有不同遗传性状生物个体间的交配相对性状即一对区分清楚的性状，或者说是同一性状的不同表现类型F1代中没有表现出来的亲代性状作为隐性性状（recessivecharacters），F1代仍然表现出来的亲代性状称为显性性状（dominantcharacters）概念

显性基因（dominantgene）即对应于显性表现型的基因，如A；隐性基因（recessivegene）即对应于隐性表现型的基因，如a。表现出来的性状，如豌豆的紫花和白花、圆型和皱型种子等叫做表现型（或表型）（phenotypes）；象AA、Aa、aa等表示个体遗传构成的则叫基因型（genotypes）。在这几种基因型中，象AA和aa两个基因相同的称为纯合体（homozygotes），其中控制显性性状的aa称为显性纯合体（homozygousdominants），控制隐性性状的aa称为隐性纯合体（homozygousrecessives）；象Aa两个基因不同的称为杂合体（heterozygotes）。Testcross.Backcrosstotherecessiveparentaltype.

F1Yy×yyYellowGreen

GametesAllarey1/2y1/2yy=green1/2Y1/2Yy=yellow

ResultsofMendel’sMonohybridcrossesParentalstrainsF2progenyRatioTallplants×dwarfplantsRoundseeds×wrinkledseedsYellowseeds×greenseedsVioletflowers×whiteflowersInflatedpods×constrictedpods

Greenpods×yellowpodsAxialflowers×terminalflowers787tall,277dwarf5474round,1850wrinkled6022yellow,2001green705violet,224white882inflated,299constricted428green,152yellow651axial,207terminal2.82:12.96:13.01:13.15:12.95:12.82:13.14:1Segregationofdomesticanimals①白毛猪×白毛猪②黄羽鸡×黄羽鸡

白毛猪：棕毛黄羽鸡：白羽鸡Dihybridcrosses:Theprincipleofindependentassortment

Yellow,roundGreen,wrinkledP×Yellow,roundF1Self-fertilized

Yellow,roundGreen,roundYellow,wrinkledGreen,wrinkledF2Observed31510810132Ratio9:3:3:1孟德尔的试验

P黄色圆粒×绿色皱粒

F1

黄色圆粒

F2

黄色圆粒绿色圆粒黄色皱粒绿色皱粒总和种子粒数31510810132556比例9：3：3：1

概念：亲本有的性状组合，叫做亲本组合（parentcombination），与亲本不同的新的性状组合，叫重组合（recombination）

图示Interpretationforindependentassortment

P黄圆YYRR×绿皱yyrr

F1

黄圆YyRr

F2

YRYryRyrYRYYRR

YYRrYyRRYyRrYrYYRrYYrrYyRrYyrryRYyRRYyRr

yyRR

yyRryrYyRrYyrryyRr

yyrr

自由组合定律的验证

F1黄圆YyRr

绿皱yyrr

YRYryRyrF2YyRrYyrryyRryyrryr

黄圆黄皱绿圆绿皱实得种子

55514953比例

1：1：1：1ExtensionsofMendel’slaws

AllelicvariationandgenefunctionGeneaction:fromgenotypetophenotypeAllelicvariationandgenefunction显色的不同表现completedominance完全显性

incompletedominance不完全显性codominance等显性overdominance超显性Incompletedominance

不完全显性P卷羽FF×正常羽ff

F1

轻度卷羽Ff

F21/4卷羽：2/4轻度卷羽：1/4正常羽

FfFfffincompletedominance不完全显性codominance等显性

P红色牛×白色牛

F1

沙毛

F21/4红色：1/2沙毛：1/4白毛overdominance超显性白眼纯合体（W/W）×野生型纯合体（W+/W+）

W+W

荧光色素含量Geneticprinciplesforovertwopairsofgenes两对以上基因的遗传规律

Geneno.基因对数Phenotypeno.完全显性时F2代表型数Gameteno.inF1F1代形成的配子数PossiblecombinationsF1代配子可能组合数Segregationration分离比1234..n24816..2n24816..2n392781..3n(3+1)1(3+1)2(3+1)3(3+1)4..(3+1)n

Geneaction:fromgenotypetophenotype

基因间的相互作用A-B-A-bbaaB-aabb9:3:3:112:3:110:3:39:6:19:4:315:113:312:410:69:7Complementation

互补作用

PRosePeaRRpprrPPF1Walnut胡桃冠

RrPpF29Walnut:3Pea:3Rose:1SingleR_P_rrP_R_pprrppEpistasis上位作用

PBlackmiceCCaa

WhitemiceccAA

F1GrayishCcAa

F29Grayish：3Black：4White9C_A_3C_aa3ccA_+1ccaa

Inhibition抑制作用PWhiteLeghornIICC

WhiteRockiicc

F1白羽黑斑点鸡IiCc

F27白鸡：6白羽黑斑点鸡：3有色鸡

I_cc+IIC_+iiccIiC_iiC_

Duplication重叠作用P阴囊疝公猪h1h1h2h2

正常母猪H1H1H2H2

正常公猪H1H1H2H2

外表正常母猪h1h1h2h2

F1正常H1h1H2h2

F215正常1阴囊疝公猪外表正常母猪

9H1_H2_+3H1_h2h2+3h1h1H2_1h1h1h2h2

Formulatingandtestinggenetichypotheses

孟德尔遗传数据的统计处理Probability概率（self-study自学）TheChi-SquareTest适合性检验（self-study自学）MendelianPrinciplesinAnimals

畜禽质量性状的遗传方式

QuantitativetraitsandQualitativetraits

数量性状与质量性状Quantitativetraits数量性状是指生物个体间连续的变异Qualitativetraits质量性状是指生物个体间不连续的变异Classificationofqualitativetraits质量性状的分类Variationsobservedwitheyessuchascolours,andforms用肉眼观察到的遗传变异，例如毛色，肤色，外形Variationsdetectedbyimmunological,biochemicalandphysicalmethods用免疫学方法，生物化学方法以及物理学方法等手段确定的变异Geneticdefectionandlethaltraits

遗传缺陷与致死性状Variationsobservedwitheyes–colours

肉眼观察到的性状—毛色

Phenotypesofhaircolorsincattlearedeterminedbymorethan20loci,inwhichtherearelocusRforredhair,locusBforblack,locusSforcolorphenotype,locusDforlightcolor,locusWhforwhite牛的毛色据认为由20多个基因座决定，这些基因座主要包括红色基因R、黑色基因B、颜色生成基因S、稀释基因座位D、白色基因Wh等Variationsobservedwitheyes–colours

肉眼观察到的性状—毛色Haircolorofswine(猪的毛色)Hairsofswineshowwhite,pureblack,brown-red,withwhitering,andetc.Phenotypesofswinehairsaredeterminedby5locisuchaslocusCforcolor,locusBforcolorphenotypes,andetc.类型有白色、纯黑色、棕红色以及白环带、花斑和污白毛等，它们由色素合成强度基因C、色素生成基因B、色素分布部位基因A等5个基因决定Variationsobservedwitheyes–colours

肉眼观察到的性状—毛色Chickenfeathercolor(鸡的羽色)Chickenfeathersshowwhite,black,yellow,red,silverand/orgolden,blueandbarred.Chickenfeathercolorarecontrolledby10loci.

常见的有白色、黑色、黄色、红色、银色或金色、兰色及横斑等，控制鸡羽色的基因有10个Variationsobservedwitheyes--forms肉眼观察到的性状—形态

Cattlehorn牛角的有无受一对基因P和p控制，P无角，p有角；肩峰和胸垂也受一对基因控制，有肩峰和胸垂对无肩峰和胸垂为显性猪的背型：垂背对直背不完全显性Chickencreeper鸡的爬行型：爬行性状显性，正常为隐性

Variationsdetectedbyimmunological,biochemicalandphysicalmethods

需用免疫以及生物化学或物理学方法等手段测定的性状

Bloodgroups血型Proteinpolymorphisms蛋白质多态性DNApolymorphismsDNA多态性

Geneticdefectionandlethaltraits遗传缺陷与致死性状

猪：后肢麻痹、体表水肿、上皮缺损等牛：无毛、软骨发育不全、回肠闭锁等。Questions

1.爬行鸡是由显性基因CP所控制的，请写出如下两个交配组合的试验结果中亲本的基因型，并用X2法测验后代是否符合理论比例？爬行鸡×爬行鸡→1972爬行鸡︰955正常鸡爬行鸡×正常鸡→1676爬行鸡︰1661正常鸡

2.一位养鸡户来信咨询，说他的纯种玫瑰冠鸡群中，出现了几只单冠个体，问应该怎样纯化玫瑰冠鸡群？（玫瑰冠受显性基因P决定，单冠性状由p基因决定。）

3.Rose-combchickensmatedwithwalnut-comchickensproduced15walnut,14rose,5pea,and6single-combchicks.Determinethegenotypesoftheparents.

4.ThedominantmutationPluminthefruitflyalsocausesbrownish-purpleeyes.IsitpossibletodeterminewhetherPlumisanalleleofthebrownorpurplegenes?Chapter9InheritanceofQuantitativeTraits

动物数量性状的遗传Definitionofquantitativetraits数量性状Geneticmechanismsofquantitativetraits数量性状的遗传机制Analysisofquantitativetraits研究数量性状的几个遗传参数Inbreedingandoutbreeding近交和杂交Moleculartechniquesintheanalysisofquantitativetraits数量性状分析的分子方法Definitionofquantitativetraits

数量性状Qualitativetraitsandquantitativetraits质量性状与数量性状质量性状--由单基因或简单的两对基因的互作影响的遗传性状，其变异是不连续的数量性状--变异是连续的，从最小到最大的范围内连续变动Thecasesofquantitativetraits

数量性状—例子

Humanheight人的身高：最矮者和最高者的差异可能是40厘米或多一点

Animalbodyweight畜禽的体重：如猪的180日龄体重可能在60千克到120千克间变动Definitionofquantitativetraits

数量性状—定义

象人的身高，体重以及家畜的大小，体重等这些性状，其变异是连续的，描述它们只有通过测量的方法。这样的性状叫做数量性状，它们的差异表现在量上或程度上Characteristicsofquantitativetraits研究数量性状的方法的特点Needtobemeasured必须进行度量Statisticalanalysisisnecessary必须应用统计方法进行分析归纳Itshouldbestudiedunderpopulationlevels研究数量性状以群体为对象才有意义Geneticmechanismsofquantitativetraits数量性状的遗传机制1908年提出多基因假说多基因假说的主要论点：数量性状的遗传基础是许多基因，这类基因大多数没有显隐性的区别，每一对基因对性状产生不大的影响，它们的效应是加性的，其行为符合基本的遗传规律Effectsofmultipleloci

多基因的效应Additiveeffect加性效应是多个基因对某一性状的共同效应是每个基因对该性状的单独效应的总和Dominanteffect显性效应是由等位基因间相互作用产生的效应Epistasis上位效应是由非等位基因之间的相互作用产生的效应显性效应和上位效应统称为非加性效应(non-additiveeffect)越亲遗传现象P140千克×80千克F1130千克F2

＞140千克或＜80千克越亲遗传现象的解释PA1A1A2A2a3a3×a1a1a2a2A3A3F1A1a1A2a2A3a3F2A1A1A2A2A3A3ora1a1a2a2a3a3Partitioningthevariance

数量性状表型值的剖分表型值=基因型值+环境偏差P=G+E表型值=育种值+剩余值

P=A+EAnalysisofquantitativetraits

研究数量性状的几个遗传参数Heritability遗传力Repeatability重复力Geneticcorrelationcoefficients遗传相关Heritability遗传力

VP=VG+VE或

VP=VA+VEH2=Broad-senseheritability

h2=或h2=Narrow-senseheritability

VGVPVAVPσA2σP2Repeatability重复力

重复力是不同次生产周期之间同一性状所能重复的程度重复力的意义re==VA+VEgVPσB2σB2+σw2Geneticcorrelationcoefficients

遗传相关rA=

covAxAy遗传相关的意义

σAxσAyInbreedingandoutbreeding

近交和杂交近交--是完全的或不完全的同型交配。相同基因型的交配叫同型交配Inbreedingdepression杂交--两个基因型不同的纯合子之间的交配Heterosis近交的效应-增加纯合基因对的数目近交使基因型纯合，杂交使基因型杂合近交降低群体均值，杂交提高群体均值近交使群体分化，杂交使群体一致近交加选择能加大群体间基因频率，从而提高杂种优势Heterosis杂种优势

两个亲本杂交，子一代个体的某一数量性状并不等于两个亲本的平均，而是高于亲本的平均，甚至超出亲本范围，比两个亲本都高，叫做杂种优势。表现在生活力，繁殖力，抗逆性以及产量和品质上杂种优势的解释生活力假说Thedominancehypothesis显性学说Theoverdominancehypothesis超显性学说Moleculartechniquesintheanalysisofquantitativetraits

数量性状分析的分子方法Genelociresponsibleforquantitativetraitsarecalledquantitativetraitloci(QTLs)MappingQTLshasbecomemorefeasiblewiththeadventoftechniquestodetectmolecularvariationChapter6Regulationofgeneexpression

基因表达调控Fromgenestocharacters从基因至性状的过程Regulationofgeneexpressioninprokaryotes原核生物基因表达的调节Regulationofgeneexpressionineukaryotes真核生物基因表达的调节GenesCharacters基因性状Characters性状Genes基因Environment环境DNAmRNAProtein蛋白质Fromgenestocharacters

从基因至性状的过程Theconception:onegeneonepeptide一个基因一条多肽链的概念Geneticcontrolsofmetabolism代谢作用的遗传控制Variationsingeneactionandphenocopies基因效应的变异与拟表型一个基因一种障碍物

一个基因一种酶一个基因一条多肽链Theconception:onegeneonepeptide

一个基因一条多肽链的概念底物中间产物1中间产物2产物酶A酶B酶C基因A基因B基因CGeneticcontrolsofmetabolism

代谢作用的遗传控制Variationsingeneactionandphenocopies基因效应的变异与拟表型Expressivity:Degreeofexpressionofatraitcontrolledbygene.Aparticulargenemayproducedifferentdegreesofexpressionindifferentindividuals表现度：某一基因型表达的程度。Penetrance:Thepercentageofindividualsthatshowaparticularphenotypeamongthosecapableofshowingit.外显率：表现某一特定表型个体的比例。Phenocopy:Anorganismwhosephenotype(butnotgenotype)hasbeenchangedbytheenvironmenttoresemblethephenotypeofdifferent(mutant)organism拟表型：环境因素有时引起非遗传的表型变化。Regulationofgeneexpressioninprokaryotes原核生物基因表达的调节Anabbreviatedpathwayofgeneexpressioninprokaryotes简述Operons:coordinatelyregulatedunitsofgeneexpression操纵子学说ThelactoseoperoninE.coli

大肠杆菌乳糖操纵子Anabbreviatedpathwayofgeneexpressioninprokaryotes简述Levelsatwhichgeneexpressionisregulatedinprokaryotes

3.RNAstability1.Transcription2.RNAprocessing4.Translation5.PosttranlationDNARNAtranscriptmRNAProteinFunctionperformedbyproteinOperons:coordinatelyregulatedunitsofgeneexpression操纵子学说SG1SG2SG3P1RP2OOperonStructuralgenesP1:promoterforregulatorgene;R:regulatorgene;P2:promoterforoperon;O:operatorRepressorEffectormoleculeThelactoseoperoninE.coli大肠杆菌乳糖操纵子(JacobandMonod,1961)POZY调节基因控制位点结构基因启动区操纵区-半乳糖苷酶转乙酰酶ZYRepression阻遏阻遏蛋白操纵区POInduction诱导+诱导物-阻遏蛋白复合物不能结合-半乳糖苷酶转乙酰酶乳糖渗透酶Regulationofgeneexpressionineukaryotes真核生物基因表达的调节Spatialandtemporalregulationofeukaryoticgenes真核基因的时空调控Waysofregulatingeukaryoticgeneexpression真核基因表达调控的途径Inductionoftranscriptionalactivitybyenvironmentalandbiologicalfactors环境和生物因子诱导的转录活性Molecularcontroloftranscriptionineukaryotes真核转录的分子控制Geneexpressionandchromosomeorganization基因表达和染色体结构Activationandinactivationofwholechromosomes整条染色体的激活和失活Geneexpressionandcancer基因表达和癌症Spatialandtemporalregulationofeukaryoticgenes真核基因的时空调控01020304050kbTimeofexpressionEmbryoFetusAdultUnknownPseudogeneOrganizationandtemporallyspecificexpressionofthehumanglobingenesWaysofregulatingeukaryoticgeneexpression真核基因表达调控的途径ControlledtranscriptionofDNADNA控制性转录AlternateSplicingofRNARNA剪接

CytoplasmiccontrolofmessengerRNAstability信息RNA稳定性胞质调控nucleusDNARNAmRNAPolypeptideTranscriptionProcessingTranslationCytoplasmInductionoftranscriptionalactivitybyenvironmentalandbiologicalfactors环境和生物因子诱导的转录活性Temperature:Theheat-shockgenes温度：热激基因Light:Theribulose1,5-bisphosphatecarboxylasegenesinplants光：植物的核糖体1，5-二磷酸羧基酶基因Signalmolecules:Genesthatrespondtohormones信号分子：与激素反应的基因Molecularcontroloftranscriptionineukaryotes真核转录的分子控制DNAsequencesinvolvedinthecontroloftranscription:enhancersandsilencers参与转录调控的DNA序列：增强子和沉默子Proteinsinvolvedinthecontroloftranscription:transcriptionfactors参与转录调控的蛋白质：转录因子5’3’Enhancersexon1intron1exon2intron2exon3

5’3’Enhancersexon1intron1exon2intron2exon3

Geneexpressionandchromosomeorganization基因表达和染色体结构Transcriptioninlampbrushchromosomeloops灯刷染色体的转录Transcriptioninpolytenechromosomepuffs多线染色体膨突的转录MolecularorganizationoftranscriptionallyactiveDNA转录活跃DNA的分子构造Euchromatinandheterochomatin常染色体和异染色体Geneamplification基因扩张Transcriptioninlampbrushchromosomeloops灯刷染色体的转录Activationandinactivationofwholechromosomes

整条染色体的激活和失活InactivationofXchromosomesinmammals哺乳类动物X染色体的失活HyperactivationofXchromosomesinDrosophila果蝇X染色体的高度活性HypoactivationofXchromosomesinCaenorhabditisCaenorhabditis的X染色体亚活性Geneexpressionandcancer

基因表达和癌症Tumor-inducingretrovirusesandviraloncogenus肿瘤反向病毒和病毒原癌基因Cellularhomologsofviraloncogenes:Theproto-oncogenes病毒原癌基因的细胞同源物：前原癌基因Chapter7GeneticManipulation

遗传操作DNAmanipulationDNA的遗传操作BasictechniquesusedtoclonegenesConstructionandscreeningofgenomiclibrariesThemanipulationofclonedDNAsequencesinvitroThemolecularanalysisofDNACellmanipulation细胞的遗传操作HumangenetherapyTransgenicanimalsDNAmanipulationDNA的遗传操作RecombinantDNAtechniques目的基因(thegeneofinterest)的获取目的基因与载体结合成重组DNA重组DNA分子引入受体细胞并表达转化体细胞的扩增、鉴定与筛选BasictechniquesusedtoclonegenesThediscoveryofrestrictionendonucleases限制性核酸内切酶TheproductionofrecombinantDNAmoleculesinvitro

AmplificationofrecombinantDNAmoleculesincloningvectorsRestrictionendonucleases

限制性核酸内切酶限制与修饰作用限制性核酸内切酶restrictionendonucleasesE.coliKE.